Insulator protecting device



Oct.7, 1947. H J SM;TH 2,428,391

INSULATOR PROTEC'ZQ ING DEVICE File'd Feb. 5, 1946 INVENTOR. v HAROLD J,SMITH Patented Oct. 7, 1 947 INSULATOR PRQTECTING DEVICE Harold J.Smith, Long Branch, N. J assignor to the United States of America, asrepresented by the Secretary of War Application February 5, 1946, SerialNo. 645,670

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) 4 Claims.

The invention described herein may be manusfactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

The present invention relates to antennas and more particularly to meansfor protecting antenna insulators against breakage during erection.

Certain types of antennas, and particularly portable types used in thefield for military communications, are made up of an antenna elementwhich is sustained upon, and electrically separated from, a base bymeans of an insulator. In erecting such an antenna, the usual procedureis to assemble the parts upon the ground and then raise the assembledantenna through an angle of 90. This practice puts an undue strain uponthe insulator which results, all too frequently, in the breakagethereof. Efforts have been made to strengthen the insulatorssufficiently to preclude breakage but so far these efforts have not beentoo successful.

It is therefore an object of the present invention to provide a means ofprotecting an antenna insulator against breakage during erection of theantenna, which means will not interfere with the operation of theantenna.

It is a further object to provide such a means which is nonseparablefrom the antenna and which may be operated simply and quickly.

These and other objects and advantages of my present invention, whichwill be better understood as the detailed description thereofprogrosses, are obtained in the following manner:

I provide a housing or barrel which surrounds the insulator and gripsthe lower end of the antenna element above the insulator and the upperend of the antenna base below the insulator. Said housing is tightenedinto such gripping position when the antenna is being assembled upon theground and is removed from about the insulator as soon as the antenna isin its upright position and there is no longer any undue strain upon theinsulator. The housing is so arranged that, after erection of theantenna, it may be loosened and dropped to a lower position about theupper end of the antenna base where it, in no way, interferes with theoperation of the antenna.

In the accompanying specification there is described, and in the annexeddrawings shown, what is at present considered a preferred embodiment ofmy present invention. It is however to be clearly understood that it isnot limited to said embodiment inasmuch as changes therein may be 2 madewithin the true spirit and scope of the claims hereto appended.

In the drawings:

Figure 1 is a perspective view of a portable antenna insulator assemblywhich embodies the present invention, the gripping barrel being shown inthe position taken by it when the antenna is in operation;

Figure 2 is a view similar to Figure 1, the parts being shown in thepositions taken by them during erection of the antenna, part of thebarrel being broken away for clarity; and

Figure 3 is an enlarged horizontal section taken along the line 33 ofFigure 1.

Referring now more particularly to the drawings, there is shown aninsulator assembly for a portable antenna. It includes an insulatorelement ll of dielectric material which is generally cylindrical inshape and has a fluted outer surface. Secured to the ends of saidinsulator element II are upper and lower insulator retainers l3, 15,which are metal cups encompassing the opposite ends of said insulatorelement l l.

A downwardly extending base ferrule ll, of tubular metal, provided withan outwardly extending flange [9 is secured to the bottom of the lowerinsulator retainer [5. Said base ferrule I! is receivable to a suitableantenna base or standard (not shown) of any suitable type.

An upwardly extending antenna ferrule 2i, also of tubular metal, issecured to the top of the upper insulator retainer I3. Said ferrule 21is receivable to an antenna element (not shown) of any conventional ordesired type. The said antenna ferrule 21 and upper insulator retainer13 may be provided, respectively, with a wiping electrical contact 23and a binding post 25, for electrical connection between the antennaelement (not shown) and a radio set (not shown).

Encircling the insulator retainers l3, l5 and the insulator II is agripping barrel 2'! which is a split sleeve of metal provided with apair of inwardly extending tabs 29 at its lower end. Said grippingbarrel 2'! is provided with two locking members, each of which includesan arcuate shaped lever arm 3!, one end of which is pivotably secured tothe barrel 21 by means of a fulcrum pin 33. Each locking member alsoincludes a bow spring 35, which is an arcuate shapedstrap ofspringymetal, terminating at each end in a loop. A pivot pin 31, extendingthrough one of said loops, is secured to the barrel 21, on the oppositeside of the split of said barrel from the fulcrum pin 33. Another pin39, extending through the other loop of said spring 35, is

fastened to the lever arm 3| a short distance out from the fulcrum pin33.

In the operation of the structure just described, when an antennaincorporating the said structure is being assembled upon the ground, thegripping barrel 2? is positioned as shown in Figure 2 so that itsopposite ends surround the upper and lower insulator retainers I3, l andthe tabs 29 abut the bottom of the lower insulator retainer IS. Thelocking members are then closed by snapping the two lever arms 3|inwardly against the gripping barrel 2'! (as shown in Figure 2). Thiscauses the interior of said barrel 21 to tightly grip the upper andlower retainers l3, l5. When the assembled antenna is then raised fromthe ground to an upright position, all of the strain of the antennaelement secured to the antenna ferrule 21 is carried by the grippingbarre} 21 and there is no strain at all upon the insulator element llitself.

After the antenna is finally fixed in its upright operating position,the two lever arms 3| may be snapped outwardly to the positions (shownin Figures 1 and 3), whereupon the gripping barrel 21' no longer "ripsthe insulator retainers l3, l5 and it may be slid downwardly until thetabs 29 abut the upper surface of the flange [9 (as shown inFigure 1).The locking barrel 21, in that lowered position, will not interfere withthe operation of the antenna.

What is claimed is:

1. In an antenna, an antenna base, an insulator element secured to theupper end of said base,

an antenna element secured to the upper end of said insulator element, asplit gripping barrel adapted in its operating condition to bepositioned about the insulator element and in its nonoperating conditionto be slid longitudinally away from said insulator element, means tocause the split gripping barrel to tightly grip the upper end of theantenna base and the lower end of the antenna element when said barrelis in its operating condition.

2. In an antenna, an antenna base, a base ferrule adapted to be attachedto said base, an insulator element secured to the upper end of said baseferrule, an antenna ferrule secured to the upper end of said insulatorelement, a split gripping barrel adapted to surround said insulatorelement and securely grip both of said ferrules, means to release thegripping barrel from said ferrules so that it may be slid downwardlyabout the base ferrule.

3. The combination of an insulator element, an antenna base secured toone end thereof, an antenna element secured to the opposite end thereof,a stiii gripping member adapted to extend between said antenna base andantenna element and rigidly grip both of them, and means to release saidgripping member from said antenna base and antenna element.

4. In an antenna, an insulator element, a pair of insulator retainerssecured respectively to the opposite ends of said insulator element, asplit gripping barrel adapted in its operating condition to encirclesaid insulator element and both of said retainers and to tightly gripboth of said retainers and in its nonoperating condition to be slidablelongitudinally away from said insulator element and at least one of saidretainers, means upon said barrel for reducing its inside size to enableit to grip the retainers aforesaid, said means including a lockingmember comprising a lever arm pivotably secured to the barrel to oneside of its split, a bow spring one end of which is pivotably secured tosaid barrel at the opposite side of said split and the other end ofwhich is pivotably secured to said lever arm a short distance out fromthe barrel.

HAROLD J. SMITH.

REFERENCES CITED The following references are of record in the his ofthis patent:

UNITED STATES PATENTS Number Name Date 204,770 Smith June 11, 18781,369,913 Brunhoif Mar. 1, 1921 1,949,162 Bodendieck Dec. 19, 19331,751,827 Marshall Mar. 25, 1930 1,144,471 Gustafson June 21, 1915FOREIGN PATENTS Number Country Date 74,175 Switzerland Feb. 1, 1917

